package com.hmdp.utils;

import cn.hutool.core.date.DateTime;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    /*首先需要记录当前开始的时间戳
     * */
    private static final long BEGIN_TIMESTAMP=1640995200L;
    // 序列号移动的位数
    private static final long COUNT_BITS=32;

    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate){
        this.stringRedisTemplate=stringRedisTemplate;
    }
    public long nextId(String keyPrefix){
        // 1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long beginTimestamp = BEGIN_TIMESTAMP;
        long timestamp=nowSecond- beginTimestamp;

        // 2. 生成序列号
        // 2.1获取当前的日期
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        // 2.2 自增长
        long count=stringRedisTemplate.opsForValue().increment("icr:"+keyPrefix+":"+date);

        //3. 拼接并返回
        return timestamp<<COUNT_BITS | count;

    }
    /*public static void main(){
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 0, 0, 0);
        long second= time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second = " + second);
    }*/
}
